Select all the cells in column B - Let's assume that B2 is the first of your actual data cells -
then use Format / Conditional Formatting... Select the "Formula is" option, and use the formula

=MAX(($A$2:$A$XXX=A2)*$B$2:$B$XXX)=B2

replacing the XXX with the row number of your bottom-most entry. Then set the formatting to a red
background, for example.

HTH,
Bernie
MS Excel MVP


"calibansfolly" wrote in message
oups.com...
Column A has a series of customer numbers and column B has each
contribution from that customer. Is there a way to somehow mark the
largest value in column B for each unique value in column A?